Contact for electric controllers or switches.



A. WHITE. CONTACT FOB ELECTRIC CONTROLLERS 0R SWITCHES.

APPLICATION FILED SDI-"L10, 190a.

9 1 3,08 1 Patented Feb. 23, 1909.

FIG.I F/G.2 d e WWW: WW; I

UNITED STATES PATENT OFFICE.

ALFRED WHITE, OF SUNDERLAND, ENGLAND.

No. 913,081 Specification of Letters Patent. Patented Feb. 28, 1909.

Application filed September 10, 1908. Serial No. 452,491.

To all whom it may concem:

Be it known that I, ALFRED WHITE, :1 subject of the King of Great Britain and Ireland, and a resident of Sunderland, in the county of Durham, England, have invented certain new and useful Improvements in or Relating to Contacts for Electric Controllers or Switches, of which the following is a specification.

This invention relates to contacts for electric controllers or switches and has special reference to contact fingers havin reversible and renewable contacts, and it as for its object to rovide an improved arrangement of reversi 1e and renewable contact which will be simpler and more easy to manufacture than those at present in use.

Accordin to this invention a reversible and renewa le contact is secured to a contact finger or carrier by a screw passing through the contact and into the end of the finger or carrier, and the contact is provided with extensions, wings or shoulders, preferabl rounded, for contacting with the contro ler drum or the like, and the rear face of the contact is furnished with a semicircular or othersuitable enlargement, projection or the like adapted to seat or rest in or on a correspondin recess or the like in or on the end of the ger or carrier and prevent turnin of the contact in use and to insure a goo contact between the contact and the or or carrier.

will fully describe my invention with reference to the accompanying drawings wherein Figure 1 is an end view, Fig. 2 a side view, Fig. 3 a Ian and Fig. 4 a plan artly in section of a controller contact ma e in accordance therewith. Fig. 5 is a similar view to Fig. 4 showing the contact reversed when worn.

Referring to the drawings, the contact piece a is secured to the finger b by a screw 0 passin through the contact piece and into the on of the finger. The contact iece a is formed with wings or shoulders d for contacting with the controller drum and with an enlargement or rib e which seats or rests in a corresponding groove or recess in the end of the finger b and prevents turning of the contact piece a when in use.

l/Vhen one of the wings or. shouldcrs d d is worn as shown in Fig. 4 he contact piece a can be reversed to bring the other wing or shoulder into position for use as shown in Fig. 5.

A spring washer or the like maybe interposed between the head of the screw 0 and the contact piece a to prevent the screw working loose in use.

By formin or providing the reversible and renewab e contact with extensions, wings or shoulders suchas described and shown, a further advantage is secured, namely that when the contact is worn down by use the relatively small area of contact surface exposed (f) as compared with previously known renewable contacts, tends to reduce the amount of arcing between the contact and the conducting segments or plates on the drum when the same leave the contact.

What I claim and desire to secure by Letters Patent is 1. In contacts for electric controllers or switches, c reversible and renewable contact piece adapted to be secured to the finger or carrier by a screw plassin through the contact piece and into t e end of the finger or carrier said contact piece havin wings or shoulders for contacting with t e controller drum or the like, and an enlargement or the like adapted to seat or rest in a corresponding groove or the like in the finger or carrier, substantially as set forth.

2. In a contact for electric controllers or switches, a contact carrying arm, a reversible metallic contact piece provided with elongated transversely disposed contact portions along opposite edges thereof, and having a fiat rear surface and a fastening means forclamping the rear surface of the metallic contact piece fiat against the end of the contact carrying arm,-the adjacent portions of said arm and contact piece being provided with interfitting portions preventing relative movement thereof.

the end thereof, a metallic contact piece. having a substantially fiat rear surface adapted to seat upon the flat bearin surface of the contact arm and provide with elongated rounded shoulders upon opposite f edges thereof and a fastening screw passing through the contact piece and serving to de-- 10 tachably clamp the same to the contact arm.

In 'witness whereof, I have hereunto signed my name in the presence of two subscribing Witnesses. p 1 ALFRED IITE. Witnesses:

THoMAs LAING WHITEHEAD, HERBERT HOWARD. 

